Compositions and methods for treating metal surfaces



Z a z i moss REFERENCE 2,955,087 3' Ice Patented Oct. 4, 1960 United States Patent other deposits from these metal surfaces without adverse effect upon the metal or metal alloys. Also, it is very 2955087 desirable to provide acid compositions which have inhib- COMPOSITIONS AND METHODS FOR TREATING ited corrosion activity and which, therefore, may be METAL SURFACES 5 shipped and stored in conventional metal containers.

In accordance with the present invention, it has now Charles Elbreder 14 Lynnbmok Drive Frontenac been found that metal surfaces may be effectively cleaned figl fif g g ii gzg i gg fi gi 3: and acid-soluble deposits removed therefrom without resultant attack or corrosion of the metal by means of a ward J. Ross, all of Lemay, Mo.

composition compnsmg hydrochlor c acid, sulfurrc acid, No Drawing. Filed Apr. 8, 1957, Ser. No. 651,131 sulfa ie acid or phosphorjgacid and an isggyiggligium 10 C] (CL 25%136) compound of the general formula:

This invention relates to compositions and methods for 15 treating metal surfaces and more particularly to composi- N tions and methods which are useful in the cleaning and x removal of deposits from metal surfaces without adverse effect upon the metal, and to inhibited acid compositions wherein R represents a higher alkyl radical d X meihmis 9 inhibiting corrosion metal surface sents a halogen atom. It has also been found that the 8 the 9 015961151111 i inclusion of one of these isoquinolinium compounds in i This application 1s a contrnuatron-m-part O 0111 the aforementioned acids gives inhibited compositions i Pefldlng appllcailoll Seflal 5 82,937, filed May 7, 1956, which may be shipped or stored in metal containers. The now fibaiidoiieiiinclusion of small amounts of one of the isoquinolinium Br efly, thamentmls ltectedtaa.QI BQ$ 1Q l f?! compounds of the class described above in the novel l lii fl l ig iii i y g s.QPERI QE.. XlLi 2 fl compositions of the invention effectively inhibits the cor- E ui-599 i i i e 0 P Ph QBFi i: a rosive action of the acid compound upon metals, but does I 9Iii29li diiFl i .59 13 PLEQQBQPPQ 9i: not impair the action of the acid upon scale and other gg jggifg 2111a! deposits commonly found upon metallic surfaces.

It is preferred that the isoquinolinium compound em- R ployed be one of the above formula wherein R is a higher alkyl radical having from 8 to 18 carbon atoms. Mixr. tures of such isoquinolinium compounds are also suitable k 35. for use in the practice of the invention. These isoquino linium compounds are effective to inhibit the corrosive action of the commonly used acids, namely, hydrochloric acid, sulfuric acid, sulfamic acid and phosphoric acid.

Only a small amount of the isoquinolinium compounds described above is necessary to protect metal and metal alloys from attack by the acids employed for the removal of scale and acid-soluble deposits or to protect metal surfaces from corrosion during the shipment and storage of such acids. It is preferred that between approximately 0.01% to 2 by weight of the isoquinolinium compound, based upon the weight of the acid compound, be included in the compositions of the invention. The amount of isoquinolinium compound employed may vary according of novel inhibited acid compositions; the provision of conto the Paiiicuiar acid used; i qi'i flili i i li ii. as

f y. .ueisht..9 ..the. s ui t l mum co o e venient and economical methods for cleaning metal sur- Sifaces; and tl re provisio1 1 of t ods itin corrol Q E E JLiQ v iliii i...i of iiii acid; Whereas sion of a metal surface against the action of certain acids. higher. amounts, as 1% 3 g i' eXamPifi, Other objects and features will be in part apparent and in shoiiid be P Y with compositions l l lngfil lfl ll \part pointed out hereinafter. i dnhydl' ch qt c QQiQWQ ZP Q-QQK P it The invention accordingly comprises the products and The novel compositions of the invention are introduced methods hereinafter described, the scope of the invention into slfsiems, having metal and are effective in b i indicated in the f ll i claims removing acid-soluble deposits from such surfaces without It has been commcn to em 10 acids such as hxdrm corroding or otherwise affecting the metal in the surface. p y Also, the compositions may be used for other purposes chloric acid, sulfuric acid, sulfamic acid and hosphoric 3cm eamng, pic g ovmg oxides Scae and for which the acid component 1s useful, the lsoqurnoother acid-soluble deposits from metallic surfaces. While linium compound therein servingto Prevent such acids are effective in removing deposits from the metal e exposed to the acid component as interior of Water Pipes, fittings and metallic surfaces gem transportation and storage thereof. Moreover, 1t has erally, their use is objectionable since the acids frequently P P i that the usffuineiis of the compositionspitme attack and corrode free metal surfaces exposed by the invention 1s not materlally affected by heat or variations removal of the deposits. Various inhibitors have been in the concentration of the add employed for removing developed to control the action of these acids against iron scale deposits: and other metals. However, none of the inhibitors used The following examples illustiati the inventionwherein R represents a higher alkyl radical and X represents a halogen atom. The invention also includes inhibited acid compositions and novel methods of treating metal surfaces and inhibiting corrosion of metal surfaces.

Among the several objects of the invention may be 40 noted the provision of compositions for treating metal surfaces; the provision of compositions of the class described which are useful to clean and remove deposits from metal surfaces without deleteriously affecting the metal or metal alloys present; the provision of composi- 45 tions of this type in which the corrosive action of hydrochloric acid, sulfuric acid, sulfamic acid and phosphoric acid on metal and metal alloys is inhibited; the provision heretofore have been completely satisfactory in control- Example 1 ling the attack of these acids on metals, including zinc, zinc alloys, steel, copper and other metals. It is highly A composition for treating a metal surface was predesirable to provide a composition for removing scale and pared containing hydrochloric acid (6% by weight) and lauryl isoquinolinium bromide (1% by weight, based upon the weight of the hydrochloric acid).

Example 2 A composition for treating a metal surface was prepared containing hydrochloric acid (6.5% by weight) and lauryl isoquinolinium bromide (0.2% by weight, based upon the weight of the hydrochloric acid).

Example 3 A composition for treating a metal surface was prepared containing sulfamic acid (6.5% by weight) and a mixture (0.5% by weight, based upon the weight of the sulfamic acid) of a major amount of lauryl isoquinolinium bromide and a minor amount of mixed alkyl isoquinolinium bromide compounds in which the alkyl groups contained from 8 to 18 carbon atoms.

Example 4 A composition for treating a metal surface was prepared containing sulfamic acid (6.5% by weight) and lauryl isoquinolinium bromide (0.01% by weight, based upon the weight of the sulfamic acid).

Example 5 A composition for treating a metal surface was prepared containing hydrochloric acid (6.5% by weight) and lauryl isoquinolinium chloride (1% by weight, based upon the weight of the hydrochloric acid).

Example 6 A composition for treating a metal surface was prepared containing hydrochloric acid (14% by weight) and lauryl isoquinolinium bromide (1% by weight, based upon the weight of the hydrochloric acid).

Example 7 An inhibited acid composition was prepared containing phosphoric acid (75% by weight) and lauryl isoquinolinium bromide (1% by weight, based upon the weight of the phosphoric acid).

Example 8 Two beakers, one containing the composition described in Example 1 (200 ml.) and the other containing hydrochloric acid (200 ml., 6% by weight) were employed, the latter beaker serving as a control. A galvanized steel strip test specimen (1" x 4") was placed in each beaker, and the time required for the galvanized coating to be stripped from the specimen was noted. In the case of the control beaker, the galvanized coating was completely stripped from the test specimen within ten minutes, whereas after a period of twenty-four hours there was no significant effect on the galvanized coating of the specimen in the beaker containing the composition of Example 1.

Example 9 Example 8 was repeated, except that one beaker contained the composition described in Example 3, and the control beaker contained sulfamic acid (6.5% by weight). It was found that the galvanized coating was completely stripped from the test specimen in the control beaker within forty-five minutes, whereas after a period of twenty-four hours there was no significant effect on the galvanized coating of the specimen in the beaker containing the composition of Example 3.

Example 10 Two beakers, one containing the composition described in Example 6 (800 ml.) and the other containing hydrochloric acid (800 ml., 14% by weight), were employed, the latter beaker serving as a control. A carbon steel strip test specimen (22 gauge 1" x 5") was placed in each beaker, and the weight loss determined after a period of 288 hours. It was found that the control specimen lost 6.2078 grams, whereas the specimen in the beaker containing the composition of Example 6 lost only 0.0021 grams.

Example 11 Two beakers, one containing the composition described in Example 7 (800 ml.) and the other containing phosphoric acid (800 ml., 75% by weight), were employed, the latter beaker serving as a control. A carbon steel strip specimen (22 gauge 1" x 5") was placed in each beaker, and the weight loss of each strip was determined after a period of 288 hours. It was found that the control specimen lost 7.5454 grams, whereas the specimen in the beaker containing the composition of Example 7 lost only 0.0032 grams.

Example 12 Two beakers, one containing the composition described in Example 6 (800 ml.) and the other containing hydrochloric acid (800 ml., 14% by weight), were employed, the latter beaker serving as a control. A copper test specimen (%i" x 1" x 5") was placed in each beaker, and the weight loss of the specimen was determined after a period of 72 hours. It was found that the control specimen lost 914 mg., whereas the specimen in the beaker containing the composition of Example 6 lost only 132 mg.

Example 13 Two beakers, one containing the composition described in Example 1 (800 ml.) and the other containing hydrochloric acid (800 ml., 6% by weight), were employed, the latter beaker serving as a control. A copper test specimen /s" x 1" x 5") was placed in each beaker, and the weight loss for each of the specimens was determined after a period of 72 hours. It was found that the control specimen lost 1724 mg., whereas the specimen in the beaker containing the composition of Example 1 lost only mg.

Example 14 Static immersion tests were carried out by immersing test strips of SAE 1010 steel in 77% solutions of phosphoric acid at F. containing varying amounts of lauryl isoquinolinium bromide. It was found, on the basis of exposure for a 24-hour period, that the inclusion of 0.03% by weight of lauryl isoquinolinium bromide was suflicient to reduce the corrosion rate of the steel test strips to approximately 2.78 mils/year, whereas the corrosion rate of control strips of SAE 1010 steel in 77% phosphoric acid not containing lauryl isoquinolinium bromide amounted to over 1000 mils/year.

It will be understood that compositions containing hydrochloric acid, sulfuric acid, sulfamic acid or phosphoric acid and alkyl isoquinolinium halide compounds other than those mentioned above give results comparable to those described in the foregoing examples.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As various changes could be made in rthe above methods and products without departing from the scope of the invention, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. An acid composition having an inhibited corrosion activity relative to metal surfaces comprising an acid selected from the group consisting of hydrochloric acid, sulfuric acid, sulfamic acid and phosphoric acid, and approximately 0.01% to 2% by weight, based upon the weight of said acid compound, of a compound selected from the group of compounds of the general formula:

wherein R represents an alkyl radical having from 8 to 18 carbon atoms and X represents a halogen atom.

2. An acid composition having an inhibited corrosion activity relative to metal surfaces comprising hydrochloric acid and approximately 0.01% to 2% by weight, based upon the weight of said acid, of lauryl isoquinolinium bromide.

3. An acid composition having an inhibited corrosion. activity relative to metal surfaces comprising sulfuric acid and approximately 0.01% to 2% by weight, based upon the weight of said acid, of lauryl isoquinolinium bromide.

4. An acid composition having an inhibited corrosion activity relative to metal surfaces comprising sulfa-mic acid and approximately 0.01% to 2% by weight, based upon the weight of said acid, of lauryl isoquinolinium bromide.

5. An acid composition having an inhibited corrosion activity relative to metal surfaces comprising phosphoric acid and approximately 0.01% to 2% by weight, based upon the weight of said acid, of lauryl isoquinolinium bromide.

6. The method which comprises contacting a metal surface with a composition containing an acid selected from the group consisting of hydrochloric acid, sulfuric acid, sulfamic acid and phosphoric acid, and approximately 0.01% to 2% by weight, based upon the weight of said acid, of a compound selected from the group of compounds of the general formula:

wherein R represents an alkyl radical having from 8 to 18 carbon atoms and X represents a halogen atom.

7. The method which comprises contacting a metal surface with a composition containing hydrochloric acid and approximately 0.01% to 2% by weight, based upon the weight of said acid, of lauryl isoquinolinium bromide.

8. The method which comprises contacting a metal surface with a composition containing sulfuric acid and approximately 0.01% to 2% by weight, based upon the weight of said acid, of lauryl isoq-uinolinium bromide.

9. The method which comprises contacting a metal surface with a composition containing sulfamic acid and approximately 0.01% to 2% by weight, based upon the weight of said acid, of lauryl isoquinolinium bromide.

10. The method which comprises contacting a metal surface with a composition containing phosphoric acid and approximately 0.01% to 2% by weight, based upon the weight of said acid, of lauryl isoquinolinium bromide.

References Cited in the file of this patent UNITED STATES PATENTS 1,678,775 Gravell July 31, 1928 2,220,451 Hunt Nov. 5, 1940 2,450,861 Robinson Oct. 5, 1948 2,472,400 Bond et al. June 7, 1949 2,606,873 Cardwell et al. Aug. 12, 1952 2,662,857 Carroll Dec. 15, 1953 2,780,653 Macy Feb. 5, 1957 2,814,593 Beiswanger Nov. 26, 1957 FOREIGN PATENTS 397,553 Great Britain Aug. 28, 1933 418,919 Great Britain Nov. 2, 1934 OTHER REFERENCES Mann et al.: Ind. Eng. Chem, February 1936, p. 160. 

1. AN ACID COMPOSITION HAVING AN INHIBITED CORROSION ACTIVITY RELATIVE TO METAL SURFACES COMPRISING AN ACID SELECTED FROM THE GROUP CONSISTING OF HYDROCHLORIC ACID, SULFURIC ACID, SULFAMIC ACID AND PHOSPHORIC ACID, AND APPROXIMATELY 0.01% TO 2% BY WEIGHT, BASED UPON THE WEIGHT OF SAID ACID COMPOUND, OF A COMPOUND SELECTED FROM THE GROUP OF COMPOUNDS OF THE GENERAL FORMULA: 